Neutrino mass and leptogenesis

We show that the seesaw mechanism may explain two independent physical parameters, small neutrino masses and universe's baryon- number asymmetry. The seesaw mechanism, thus, provides us with a big dream to relate the present baryon asymmetry to observables in neutrino physics. We show a simple model that can predict the sign of CP violation in low-energy neutrino oscillations provided that the baryon number in the present universe is positive. (17 refs).